Walk the Line

Kinesin (3Kin)

Outline

Structure:

-Kinesin is a type of motor protein found in eukaryotic cells

-Its structure is a dimer, it includes two heavy chains (which are called the motor domains) and two light chains (α-helical stalks)

-The image seen here is from PyMOL, and it was used to separate the individual chains/proteins from larger complexes

-PyMOL can be used to learn about molecular structures including molecular size, bond lengths/angles, and specific sites of inter/intramolecular forces (important for binding of ligands)

Conserved:

-The motor domains contain highly conserved regions, which is expected because these are the sites of microtubule and ATP (discussed later) binding.

-These regions cannot change much or binding would not commence.

Function:

-Kinesin proteins move across microtubules and its main functions include transport and motility

-The motor domains contain 2 binding sites, 1 for ATP and 1 for microtubules

-Movement along the microtubules is powered by hydrolysis of ATP to ADP

-Hydrolysis of ATP causes a conformational change which leads to “power strokes”

-Kinesintransport a wide range of structures including vesicles and organelles, and are also important in chromosome movement during cell division

Diseases:

– Spactic Paraplegia

– Polycystic Kidney Disease

– Alzheimer’s Disease

– Salmonella

Link to Powerpoint